Sistema renina-angiotensina (SRA) en las patologías cardiovasculares: papel sobre la hipertensión arterial / Renin-angiotensin system (RAS) in cardiovascular pathologies: role on arterial hypertension

INTRODUCCIÓN: En las patologías cardiovasculares como insuficiencia cardiaca, hipertensión arterial, vasculopatías, enfermedades coronarias, etc; el sistema renina-angiotensina (SRA) tiene participación clave, cuyas acciones principales incluyen la regulación de la presión arterial, el tono vascular, la volemia y facilitar la transmisión simpática. OBJETIVO: En este ensayo se discuten estos aspectos del SRA como resultado de una secuencia de transformaciones de distintas proteínas, comenzando por la acción de la renina que transforma el angiotensinógeno en angiotensina-I y posteriormente, este se convierte en angiotensina II por acción de la enzima convertidora de angiotensina I (ECA I). CONCLUSIONES: Cuando este sistema se ve alterado culmina en hipertensión arterial, la cual se puede controlar mediante tratamientos farmacológicos empleando inhibidores químicos cuyos mecanismos de acción se basan en impedir que estas enzimas se unan a su sustrato y así se mantenga un equilibrio homeostático en la presión arterial

INTRODUCTION: In cardiovascular pathologies such as heart failure, arterial hypertension, vasculopathies, coronary diseases, etc; the renin-angiotensin system (RAS) has an essential role. The main actions include the regulation of blood pressure, vascular tone, volemia and facilitating sympathetic transmission. OBJECTIVE: This manuscript summarizes these aspects of the SRA and discussed the sequence of transformations of different proteins, beginning with the action of renin that transforms the angiotensinogen into angiotensin-I and later, it is converted into angiotensin II by the action of the Angiotensin-I converting enzyme (ACE-I). CONCLUSIONS: When this system is altered culminates in hypertension, which can be controlled by pharmacological treatments using chemical inhibitors whose action mechanisms are based on preventing these enzymes from binding to their substrate and thus maintain a homeostatic balance in the pressure arterial

In vitro renin-angiotensin system inhibition and in vivo antihypertensive activity of peptide fractions from lima bean (Phaseolus lunatus L.).

BACKGROUND: The renin-angiotensin system is key in the physiopathology of arterial hypertension because it converts angiotensin I, via angiotensin I-converting enzyme (ACE), into angiotensin II. In vitro analyses were done of the ACE-inhibitory and renin-inhibitory activities of peptide fractions isolated by enzymatic hydrolysis of lima bean (Phaseolus lunatus) protein. Antihypertensive activity was confirmed in vivo using a rat model. RESULTS: Lima bean protein was hydrolyzed with one of two sequential enzymatic systems (pepsin-pancreatin or Alcalase®-Flavourzyme®). Ultrafiltration of the hydrolysates produced fractions of different molecular weights. The >3 kDa fraction of the pepsin-pancreatin hydrolysate had the highest ACE-inhibitory activity (60.15%, IC50: 172.62 µg mL-1 ), while the >3 KDa fraction of the Alcalase®-Flavourzyme® hydrolysate had the highest in vitro renin-inhibitory activity. A weak correlation (r = 0.44) was found between ACE-inhibitory and renin-inhibitory activities. When tested in vivo, the latter fraction lowered systolic blood pressure by 64% and diastolic blood pressure by 51%. CONCLUSION: Peptide fractions from lima bean Phaseolus lunatus protein hydrolysates exhibit both in vitro and in vivo antihypertensive activity. Bioactive peptides from lima bean have potential applications as ingredients in functional foods. © 2017 Society of Chemical Industry.

Chemical and Functional Properties of Chia Seed (Salvia hispanica L.) Gum.

Chia (Salvia hispanica L.) constitutes a potential alternative raw material and ingredient in food industry applications due to its dietary fiber content. Gum can be extracted from its dietary fiber fractions for use as an additive to control viscosity, stability, texture, and consistency in food systems. The gum extracted from chia seeds was characterized to determine their quality and potential as functional food additives. The extracted chia gum contained 26.2% fat and a portion was submitted to fat extraction, producing two fractions: gum with fat (FCG) and gum partly defatted (PDCG). Proximal composition and physicochemical characterization showed these fractions to be different (P < 0.05). The PDCG had higher protein, ash, and carbohydrates content than the FCG, in addition to higher water-holding (110.5 g water/g fiber) and water-binding capacities (0.84 g water/g fiber). The FCG had greater oil-holding capacity (25.7 g oil/g fiber) and water absorption capacity (44 g water/g fiber). In dispersion trials, the gums exhibited a non-Newtonian fluid behavior, specifically shear thinning or pseudoplastic type. PDCG had more viscosity than FCG. Chia seed is an excellent natural source of gum with good physicochemical and functional qualities, and is very promising for use in food industry.